The Search for a New Gene in Synapse Formation

Neurons are cells that make up the sophisticated network of our brain. These cells interact with other neurons to form connecting structures called synapses. The Herman lab is interested in understanding the genes and molecular mechanisms behind this process. Neurons in vastly different species share many of the same properties. This allows us to study homologous genes in the fruit fly to gain a better understanding of our own development. I am working on a mutation, 317, that prevents the formation of normal syn- apses. I began searching for the gene responsible by crossing the 317 strains with flies carrying known and easily observable genetic markers and allowing recombination to occur between the chromosomes. Whether the progeny had my phenotype or not told me which direction on the DNA strand I should look. Every test narrowed down my search interval until it became too small to use my obvious genetic markers. Currently I am using markers only observable with a PCR technique. Once I narrow down the range to approximately 10 candidate genes, I will sequence them and compare the results to wild type flies to see which variation is responsible for the 317 phenotype. The results from my early tests showed that the gene linked to this 317 mutation is located in a segment that has no known synapse formation regulatory genes indicating that this is a new discovery. With a study of homologous genes between flies and humans, these new findings will contribute to a better understanding of how our own neurons function.